This invention relates to the art of dispensing moving webs of paper, plastic and the like, in which the leading end of a fresh roll of web material has been spliced onto an expiring roll of such web material, and a portion of the web issuing from the expiring roll has been severed from the remaining portion of the roll.
Automatic web splicing apparatus for web unwind systems is known for forming butt splices or overlapping splices. The most common splicing apparatus forms an overlapping splice. The web from the expiring roll, following the splice, is severed so that a short tail of material, formerly part of the expiring web, follows the splice as it progresses through subsequent coating and/or converting stages.
The actual length of the tail, following cutting from the expiring roll, will vary in accordance with the reaction time of the knife, web speed, the particular equipment being used, and in the case of manual or semiautomatic operation, the skill of the operator. Thus, in certain manual or semi-automatic splice control systems, a two foot tail at 500 feet per minute could become a four foot tail at 1,000 feet per minute web speed.
Modern unwind systems may be programmed to take into account variables which affect tail length, so that the expiring web can always be cut at about the same length following the splice over a wide range of variables which include line speed and unwind roll diameters. For example, one such system, in combination with a turret-type winder, is described in Penrod et al, 3,253,795 issued May 31, 1966, and computer controlled versions of this system are sold by the assignee of this application, The Black Clawson Company, under the trade name "AccuTail."
While such systems are capable of stabilizing the length of the free tail, it is not usually practical in such systems to provide an overlap splice which has no tail. Even a short loose tail portion can flap around as the web is curved around rolls, and can interfere with the proper movement of the splice through downstream machinery. An unsecured trailing edge or tail can disrupt downstream processes, such as coating processes. Further, in cases where the web is rewound it may not be directly used by other processes, and an unsecured tail in a subsequent process may lead rather than follow, thereby disrupting the process or even tearing or breaking the web.
In systems which form overlapping splices, there is a need for an apparatus and method by which a free tail extending from the splice may be controlled by attaching or affixing the tail to the progressing web so that it cannot interfere with subsequent handling of the web.